The 1 ug ACTH test has been suggested to be more sensitive than the 250 ug test in the detection of adrenocortical insufficiency (AI). AI is a serious, commonly occurring disease in the HIV population. To assess the potential role of the 1 ug test in this population, the investigators performed the 1 ug and the 250 ug ACTH tests, studying patients on 2 separate days. Day 1: 1ug ACTH was given intravenously at 8AM after overnight fast and serum control was measured at 0.30 and 60 minutes. Day 2, procedure was repeated with 250ug ACTH. An absolute peak cortisol value of >18ug/dl and increment of 7ug/dl from baseline constituted a normal response. Progress report and summary of findings: Out of 23 patients, 11 (48%) had discrepant results; 9 (39%) had subnormal response to 1ug ACTH but normal to 250ug ACTH (group 1), 2 (9%) had normal response to 1ug test but subnormal cortisol increment on the 250ug test (group 2); 4 patients (18%) had concordantly abnormal results on both days suggesting adrenal insufficiency (group 3); and 8 patients (34%) had concordantly normal response on both days (group 4). 7 patients from group 1 underwent insulin tolerance test; 5 had normal responses as measured by both peak and increment values. 2 patients had normal peak cortisol values but less than a 7ug/dl increment in cortisol. Conclusion: discrepancies between 1ug and 250 ug ACTH stimulation tests are common in patients with AIDS. Studies in larger groups of patients are now in progress to determine the specificity and sensitivity for each of these tests.